<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style type="text/css">
        html, body {
            margin: 0;
            height: 100%;
        }

        canvas {
            display: block;
        }

    </style>
</head>
<body onload="draw();">
</body>
<script src="http://www.yanhuangxueyuan.com/versions/threejsR92/build/three.js"></script>
<script src="js/ParametricGeometries.js"></script>
<script src="js/utils/SceneUtils.js"></script>
<script src="js/controls/OrbitControls.js"></script>
<script src="js/libs/stats.min.js"></script>
<script src="js/libs/dat.gui.min.js"></script>
<script>
    var renderer;
    function initRender() {
        renderer = new THREE.WebGLRenderer({antialias:true});
        //renderer.setClearColor(new THREE.Color(0xEEEEEE, 1.0)); //设置背景颜色
        renderer.setSize(window.innerWidth, window.innerHeight);
        document.body.appendChild(renderer.domElement);
    }

    var camera;
    function initCamera() {
        camera = new THREE.PerspectiveCamera(45, window.innerWidth/window.innerHeight, 1, 10000);
        camera.position.set(0, 0, 150);
    }

    var scene;
    function initScene() {
        scene = new THREE.Scene();
    }

    var light;
    function initLight() {
        scene.add(new THREE.AmbientLight(0x404040));

        light = new THREE.DirectionalLight(0xffffff);
        light.position.set(1,1,1);
        scene.add(light);
    }

    //创建平面模型的方法
    var plane = function (u, v) {
        var x = u*50;
        var y = 0;
        var z = v*50;
        return new THREE.Vector3(x, y, z);
    };

    //创建波浪图形的方法
    var radialWave = function (u, v) {
        var r = 50;

        var x = Math.sin(u) * r;
        var z = Math.sin(v / 2) * 2 * r;
        var y = (Math.sin(u * 4 * Math.PI) + Math.cos(v * 2 * Math.PI)) * 2.8;

        return new THREE.Vector3(x, y, z);
    };

    var klein = function (u, v) {
        u *= Math.PI;
        v *= 2 * Math.PI;

        u = u * 2;
        var x, y, z;
        if (u < Math.PI) {
            x = 3 * Math.cos(u) * (1 + Math.sin(u)) + (2 * (1 - Math.cos(u) / 2)) * Math.cos(u) * Math.cos(v);
            z = -8 * Math.sin(u) - 2 * (1 - Math.cos(u) / 2) * Math.sin(u) * Math.cos(v);
        } else {
            x = 3 * Math.cos(u) * (1 + Math.sin(u)) + (2 * (1 - Math.cos(u) / 2)) * Math.cos(v + Math.PI);
            z = -8 * Math.sin(u);
        }

        y = -2 * (1 - Math.cos(u) / 2) * Math.sin(v);

        return new THREE.Vector3(x, y, z);
    };

    function initModel() {

        //轴辅助 （每一个轴的长度）
        object = new THREE.AxesHelper( 50 );
        scene.add( object );

        var mesh = createMesh(new THREE.ParametricGeometry(THREE.ParametricGeometries.klein, 12, 12));
        scene.add(mesh);
    }

    //生成模型
    function createMesh(geom) {

        //设置当前的模型矩阵沿xy轴偏移，让图片处于显示中心
        geom.applyMatrix(new THREE.Matrix4().makeTranslation(0, 0, 0));

        // 创建法向量纹理
        var meshMaterial = new THREE.MeshNormalMaterial({
            flatShading: THREE.FlatShading,
            transparent: true,
            opacity: 0.9
        });

        //  创建一个线框纹理
        var wireFrameMat = new THREE.MeshBasicMaterial();
        wireFrameMat.wireframe = true;

        // 创建模型
        var mesh = THREE.SceneUtils.createMultiMaterialObject(geom, [meshMaterial,wireFrameMat]);

        return mesh;
    }

    //初始化性能插件
    var stats;
    function initStats() {
        stats = new Stats();
        document.body.appendChild(stats.dom);
    }

    //用户交互插件 鼠标左键按住旋转，右键按住平移，滚轮缩放
    var controls;
    function initControls() {

        controls = new THREE.OrbitControls( camera, renderer.domElement );

        // 如果使用animate方法时，将此函数删除
        //controls.addEventListener( 'change', render );
        // 使动画循环使用时阻尼或自转 意思是否有惯性
        controls.enableDamping = true;
        //动态阻尼系数 就是鼠标拖拽旋转灵敏度
        //controls.dampingFactor = 0.25;
        //是否可以缩放
        controls.enableZoom = true;
        //是否自动旋转
        controls.autoRotate = false;
        //设置相机距离原点的最远距离
        controls.minDistance  = 20;
        //设置相机距离原点的最远距离
        controls.maxDistance  = 10000;
        //是否开启右键拖拽
        controls.enablePan = true;
    }

    //生成gui设置配置项
    var gui;
    function initGui() {
        //声明一个保存需求修改的相关数据的对象
        gui = {};
        var datGui = new dat.GUI();
        //将设置属性添加到gui当中，gui.add(对象，属性，最小值，最大值）

        //调用生成一次图形
        gui.asGeom();
    }

    function render() {
        renderer.render( scene, camera );
    }

    //窗口变动触发的函数
    function onWindowResize() {
        camera.aspect = window.innerWidth / window.innerHeight;
        camera.updateProjectionMatrix();
        render();
        renderer.setSize( window.innerWidth, window.innerHeight );

    }

    function animate() {
        //更新控制器
        controls.update();
        render();

        //更新性能插件
        stats.update();
        requestAnimationFrame(animate);
    }

    function draw() {
        initRender();
        initScene();
        initCamera();
        initLight();
        initModel();
        initControls();
        initStats();
        //initGui();

        animate();
        window.onresize = onWindowResize;
    }
</script>
</html>